Tag: sex reversal

Video credit: Charles Bernard Makuya Description: Abdel Rahman El Gamal (Founder of the video channel) Because of the superiority of tilapia males over females in regard to growth rate, several scenarios are adopted towards the culture of all-male tilapia. Whether the use of male hormone (17-alpha methyl testosterone) is permitted or banned, its use is …

This lecture has been delivered by Dr. Abdel Rahman El Gamal during August 2016 as a contribution to the “Fish Culture Development training course – Africa” which is annually organized by the Egyptian International Centre for Agriculture (EICA) with the support by Japan International Cooperation Agency (JICA). The introductory part of the lecture addressed …

After a short introduction of tilapia in aquaculture, this 17-min video focuses on the production of all-male tilapia through the sex reversal practices using male hormone. The logic sequence of the sex reversal process has been maintained to large extent starting by the sexual differentiation in tilapia then determining the appropriate age and/size for successful …

Photo credit:Kevin Fitzsimmons (USA) Review: Abdel Rahman El Gamal (Founder of the website) The photo shows a part of a tilapia hatchery facility located in Hainan Province, China. Based on various information sources, the production capacity of the said hatchery is about 400 million of sex reversed tilapia fingerlings per year. This contribution to the …

Credit: Ahmed Zaki (Egypt) The photos were taken in a tilapia hatchery in the Philippine. In this hatchery the broodstock of Nile tilapia, Oreochromis niloticus at the ratio of 3 females: 1 male. The swim-up tilapia fry are collected along the pond sides using a long-handled, narrow-mesh deep nets. The collected fry are transferred into …

Credit: Ismael Radwan (Egypt) The male hormone (17 alpha- methyl testosterone) is dissolved in alcohol at the dose of 60 milligram per 500 ml of alcohol and then after the alcohol containing hormone is to be mixed with one kg of fry feed. Treated feed is dried in shade and could be stored in freezer …

Credit: Ismael Radwan (Egypt) As established, the effectiveness of sex reversal process depends on several factors including the initial size (age) of treated fry. If the tilapia spawning and collection systems of the fry cannot guarantee the optimum size (age) of tilapia fry, a grading system will be required. The photo shows a simple grader …

Credit: Manuel Cano Alfaro (Guatemala) The first photo shows people collecting the swim-up fry of Nile tilapia (Oreochromis niloticus) from the spawning tanks. Tilapia broodstock are stocked at the ratio of four females for each male. The collected fry are passed to the sex reversal unit which is shown in the second photo. The sex reversal …